Ageing in the South Pacific. Physical changes with urbanization.

The process of ageing, the place the elderly hold in the South Pacific societies and the care they receive as they move from adult independence to geriatric dependence varies considerably in different Pacific Polynesian populations. This provides unusual opportunity to examine the physical changes of ageing in people of the same broad genetic make-up exposed to environmental changes brought about by urbanization. Epidemiological surveys carried out since 1962 among New Zealand Maoris, Tongans, Cook Island Maoris in Rarotonga and Pukapuka, and Tokelauans living in Tokelau and following migration to New Zealand, provide the main data base for this presentation. The pattern of blood pressure, body weight, serum lipids and clinical disorders show considerable variation which relate most closely to the adoption of westernized life-style and moving into an urban environment. Analysis of the ECG pattern, in Pukapukans, in whom blood pressure shows only a minor increase with age, compared with age and sex-matched subjects studied in Newcastle, England provide insights into the ageing heart. An examination of mortality based on risk factors at entry shows an inverse relationship of serum cholesterol to total mortality in New Zealand Maori men and women, in Tokelau men but not women. Increasing systolic blood pressure was related to mortality in New Zealand Maori men, Tokalau men and Caucasian women, but not in the other race sex groups. The pattern of ageing and risk factors must clearly be examined in individual populations because while death is the end the pathways vary.